Cooling apparatus for rotary kilns



Jan. 13, 1931.

F. LUTHER v COOLING APPARATUS FOR ROTARY KILNS Filed May 26. 1927 Patented Jan. 13, 1 931- UNITED STATES PATENT OFFICE FRITZ LUTHER, OF DESSAU, GERMANY, A SSIGNOB T G. POLYSIUS, '01 DESSAU, GER- MANY, A FIRM. OF GERMANY cooLme Armaarus ron ao'rnmr xnms Application filed. Iay 26, 1927, Serial No. 194,511, and in Germany October 4, 1926.

- This invention relates to rotary kilns and more particularly to the apparatus or parts,

employed therein to effect the cooling of the in varying degree by the lates.

material after the burning or other heat treatment .thereof.

I In carrying out my invention, the cooling,

zone of the drum, is provided with longitudinally extending sheet metal plates or baflles which project lnwardly from the peripheral wall and serve to support an inner cylinder through which the burner extends. This results in the subdivision of the material into an annular series of separate streams or parts arranged around and spaced from the burner inder. This construction has advantages from the standpoint of manufacture and alsoit 'efiects a better cooling action. The relative movement ofthe parts durin the ro- 'tation of thedrum and the longitudinal feeding of the material facilitates the movement of the larger pieces'ofthe clinker through the passages.

In the accompanying. -drawings, I have illustrated one embodiment of my invention.

- In these drawings:

Fig. 1- is a central longitudinal section of one end portion of a rotary kiln;

Figs. 2 and 3 are transverse sections on the lines 22 and 3 -3 respectively of Fig. 1';

- and Fig. 4 is .a central longitudinal section shown in Fi through thewhole kiln.

The invention may be applied to various types of rotary kilns, for instance, that 4 in which the material enters the .kiln at t e right hand end and passes in the directionof the arrow through a preliminary heating zone 17, a calcining zone 18 and the inner cylinder itself may move radially in respect to the outer cylto a clinkering zone 9, Beyond the clinkering zone is the cooling and discharge zone in which my improved construction may be incorporated. In this cooling zone there is mounted an inner cylinder 11 smaller than and spaced from the outer shell 16. This inner cylinder 11 is supported by a plurality of walls 12 which extend axially in approximately radial planes. Each of thesewalls or plates 12 is flexible and longitudinally curved, and they in connection with the cylinder 11 and shell 16, form an annular series of passages lengthwise of the drum outside of the cylinder 11.

As the drum rotates and the material in moving endwise reaches the end of the cyl-' inder 11 and thewalls 12, it is picked up by, the successive walls 12 and carried around the axis of the drum, and thus is subdivided into separate portions which continue their. flow lengthwise of the drum.- As these separate streams are separately agitated during the bodily circumferential movement of the passages, the material in each stream has a greater exposed. area and greater heat radiating surface. The passages also serve for the inflow of separate streams of air countercurrent to the outflowing material. Thus due to the more effective contact with the air, the more efiective agitation, and the more effective heat conduction, is effectively cooled before reaching the discharge ports 20. V

Due to the flexibility of the walls 12, the cylinder may move to a limited extent in a radial direction so that the tumbling of the material in moving through the passages and around the cylinder 11 may cause a vibration of the cylinder whichaids in the advancing of the material and the intermixing of the air therewith.

The clinkering, zone may be provided with the material suitable heat insulating lining 151, and a portion of this of reduced thickness may extend part way along the shell 16 within the pas-- sages around the cylinder 11; The very hot material coming from the clinkering zone may be preliminarily cooled by the action of the blades' 13 extending longitudinally and serving as shovels or baflles to lift up and drop the material.

I have not illustrated any means for heating the drum as such forms no portion of my invention, but it will be understood that the projects through the cylusual burner pipe to the end of the enlarged inder 11 toward or clinkering zone. 7

This construction the operation of the burner by looking through the cylinder along the burner tube, as none of the material flows out through the cylinder.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

. A rotary kiln having a cooling drum at the a discharge end thereof, a hollow cylinder within said drum open at both ends and approximately concentric with said drum and spaced from the peripheral wall thereof, and longitudinally extending curved flexible plates supportin said cylinder from said drum, whereby the annular space between the drum and the cylinder is subdivided into an annular series of separate passages for the outflow of the material, said plates belng 'of' suflicient flexibility to permit limited bodily movement of the cylinder radially of the drum, whereby the cross-sectional form of said passages varies during the rotation of the drum.

Signed at Lei zig, in the state of Sax- Znyb Germany, t 's fifth day of May, 1927,

. FRITZ LUTHER.

permits one to observe 4 

